The present invention relates to a process for the continuous treatment of particles by means of a treatment agent, as well as a device for implementing this process.
It is known to treat particles continuously by means of a solid or liquid treatment agent so as to coat them or wrap them in a surface layer for various applications. The problem to be solved in this type of technique resides in the desire both to obtain a treatment which is as uniform and even as possible and to perform the treatment economically.
In this field, processes and apparatuses have been proposed in which the particles, as well as the treatment agent previously supplied with the particles, are made to progress along the bottom of a stationary trough using a longitudinal brush coaxial with the bottom of the trough and tangent through at least one of its generatrices to the bottom of the said trough. Although this technique provides an improvement over the techniques of the prior art, it nevertheless exhibits the drawback of not affording a sufficiently uniform distribution of the treatment agent on the particles and of requiring a relatively long piece of equipment in order to obtain a satisfactory effect.
Another device has more recently been proposed, in which the principal part is a drum driven in slow rotation, in which there is disposed a brush, with a parallel but off-centered axis, rotating in a direction opposite to that of the rotation of the drum, so as to give better agitation to the particles and further to improve the uniformity of the covering of the particles.
However, these techniques still remain deficient, when it is desired to obtain a high quality of the covering in combination with high productivity.
The aim of the present invention is to overcome these drawbacks and to provide a process and a device for continuous treatment of particles combining both an excellent quality of covering and an improved productivity.